Teachers’ notes – Light at work
Synopsis
Initially, learners think about and discuss what the most common colours are in our natural and made environments. Using photographs they explore black and white and colour images and consider what effect colour filters might have. Learners explore mixing coloured lights before using video to predict and observe different spinners working before making their own. Learners design and make a kaleidoscope describing their observations and follow a set of instructions to make their own pinhole camera and explore its use. They find information about the ‘camera obscura’ and explore how to turn a room in school into a ‘camera obscura’.
Curriculum links
The sustainable Earth:
3. a comparison of the features and properties of some natural and made materials
4. the properties of materials relating to their uses
How things work:
5. how light travels and how this can be used
Skills
Communication: 1, 2 & 3
Enquiry – Planning: 2, 3, 6 & 7
Enquiry – Developing: 1, 5, 6 & 7
Enquiry – Reflecting: 5 & 6
Activities
Tab 1
/ The first tab in this activity asks learners to think about and discuss what the most common colours are in our natural and made environments. Rollovers encourage learners to carry out activities away from the computer, for example, recording the colours of living things in a local habitat, carrying out surveys to find out the most popular car colour, or children’s favourite colour.Tab 2
/ When this tab opens learners are provided with a black and white photograph of a garden. They are asked to predict what colours they would see if it was a colour photograph and to discuss and explain their ideas. By clicking on the number 2 button, learners are able to see the colour photograph so they can discuss their predictions. A rollover asks the learners to consider what this photograph might look like if it was taken through clear green plastic. By clicking on the number 3 button, they are able to see the effect on the photograph. A final rollover encourages learners to explore the appearance of a range of things as seen through different coloured acetate or cellophane.Tab 3
/ This tab asks the learners to consider how different coloured lights might appear when they are mixed together. They are encouraged to use coloured, transparent materials to cover torches, etc to explore mixing different coloured lights at first hand.Tab 4
/ When this tab opens learners are asked to watch a video of children testing out their homemade spinners and to predict what colours they think they will see when each one spins around. The video may be stopped to allow learners to discuss and predict what might happen for each spinner.Tab 5
/ This tab provides learners with a template for designing their own spinner and predicting what they think it will look like when it spins. Learners are asked to create their own spinners and carry out practical tests of their predictions.Tab 6
/ This tab utilises the tab within a tab structure. Initially, learners are asked to design and make a kaleidoscope and then to look through the viewer and to describe what they see. An internet search will provide several options for making a simple kaleidoscope or the ‘Template’ can be used to provide learners with instructions. Alternatively, learners might be supplied with the basic materials and encouraged to design and make their own after carrying out some research. After observing the kaleidoscope working, learners are encouraged to use their knowledge and understanding of light to explain their observations. Rollover questions are provided to support discussion about what might be happening inside the kaleidoscope. Learners might also draw and explain how their design works.Tab 7
/ This tab utilises the tab within a tab structure. The tab asks learners to follow a set of instructions to make their own pinhole camera. By clicking on the ‘Next’ button the learners are presented with a second tab that asks them to describe and discuss what they see when they use their pinhole camera. Rollovers encourage learners to explain how they think pinhole cameras work and how and where they think they might find more information about them.Tab 8
/ This tab utilises the tab within a tab structure. The tab asks the learners to find information about the ‘camera obscura’ and to create a 30 second presentation about what they find out. By clicking on the ‘Next’ button learners are able to open up a second tab that provides learners with details of how to turn a room in school into a ‘camera obscura’. Learners are asked to predict what they think they will see and to test out their ideas in practice.Background information
Information relating to Tab 2:
A transparent coloured material such as acetate or cellophane will act as a light filter when held up to a light. White light is made up of seven different colours of light in the visible electromagnetic spectrum – the colours of the rainbow. A filter will absorb light of all wavelengths, except light of its own wavelength. A red filter will absorb orange, yellow, green, blue, indigo and violet light but will transmit or allow through red light only.
Information relating to Tab 3:
In terms of light there are deemed to be three ‘primary colours’ – red, green and blue. When mixed they form the following colours:
Red & green – yellow
Blue & green – cyan
Blue and red – magenta
Yellow, cyan and magenta are often referred to as ‘secondary colours’.
Information relating to Tab 6:
A kaleidoscope consists of a tube of mirrors that contains loose, coloured objects such as beads and small pieces of acetate. The name is derived from Ancient Greek – kal (beauty), eido (shape or form) and scope (a tool for examination). A kaleidoscope works by using the principle of multiple reflection. As the tube is rotated the coloured objects move and reflect light. This light then reflects continuously off the mirrors the tube is constructed from producing a symmetrical pattern. If the kaleidoscope has two mirrors then the pattern formed will be isolated against a black background. If it has three mirrors joined in a triangle then the pattern will fill the whole field.
Information relating to Tab 7:
A pinhole camera is basically a box that is completely light proof apart from one very small ‘pinhole’ at the centre of one end of the box. Light passes through the pinhole and produces an inverted image on the opposite wall of the box of whatever the camera is pointing at.
Information relating to Tab 8:
A ‘camera obscura’ from Latin - camera (vaulted chamber or room) and ‘obscura’ (dark).
Historically, it was used in drawing and for entertainment and works by projecting images of its surroundings onto a screen. It is regarded as one of the main inventions that led to the creation of photography. The ‘camera obscura’ is usually a large box or a room with a hole in one side. Light from a scene will pass through the hole and hit a surface inside where it will be reproduced as an inverted image. This image may be projected onto paper and can then be traced to produce an accurate representation of the original scene. It is thought that many artists used some version of the ‘camera obscura’ in their works.
Unit 3.4.5 teachers’ notes – Light at work1